1. Field of the Invention
The present invention relates generally to optical devices and, more specifically, the present invention relates to Bragg grating optical devices.
2. Background Information
The need for fast and efficient optical-based technologies is increasing as Internet data traffic growth rate is overtaking voice traffic pushing the need for optical communications. Commonly used optical components include diffraction gratings, thin-film filters, fiber Bragg gratings, and arrayed-waveguide gratings.
A fiber Bragg grating is an optical fiber device that includes an optical fiber with periodic changes in the refractive index of fiber core materials along the fiber length, which may be formed by exposure of the photosensitive core to an intense optical interference pattern. With the changes in the refractive index along the fiber length, optical beams at a particular wavelength are reflected by the fiber Bragg grating while other wavelengths are allowed to propagate through the fiber.
A limitation with known fiber Bragg gratings is that the particular wavelength that is reflected by the fiber Bragg grating is substantially fixed. Consequently, if different wavelengths of light are to be reflected, different fiber Bragg gratings are utilized. In some known fiber Bragg gratings, nominal adjustments to the reflected wavelength may be provided by physically or mechanically stretching the optical fiber of the fiber Bragg grating to modify the length of the optical fiber. The disadvantage of this technique is that the amount of adjustment to the reflected wavelength is relatively small and the optical fiber may suffer damage from the physical stress and strain of the stretching.